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文中提出了一种基于区域和Contourlet变换相结合的图像融合新方法,新方法利用小波Contourlet变换良好的多尺度性和多方向性特征,结合Contourlet变换的多聚焦图像融合算法,得到高频和低频图像。小波Contourlet由于变换缺乏平移不变性而产生图像失真,弱边缘具有几何信息,而噪声却不具备这个性质。为了在去噪声的同时更多地保留弱边缘信息,再次利用到循环平移的方法。实验结果表明,该文方法不仅在客观评价指标上优于小波变换法,而且从主观评价上来看,文中所提方法得到的图像更加清晰。 相似文献
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The global mechanical behaviour of a 4D carbon–carbon (C– C 4D) composite material is described. Designed for aeronautic applications and particularly for the brake discs of heavy air craft, this material is a layered composite reinforced in three directions in the plane (–60°, 0°, 60°) to which the fourth direction of reinforcement is perpendicular. Having ascertained the compliance matrices in the plane to which the braking surface is parallel, we have determined the engineering constants of an elementary ply from the basic assumptions of the classical laminations theory (CLT). Finally, to construct both linear-elastic and elastoplastic constitutive equations of the C– C 4D, we propose a thermodynamic model that accurately characterises the behaviour of this material. This simple model can be identified from simple mechanical tests. 相似文献
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